Mass spectral studies of metal chelates. IV. Mass spectra, appearance potentials, and coordinate bond energies of bis(acetylacetonate)metal(II) complexes of the first transition series

Reichert, C.; Westmore, John B.

doi:10.1021/ic50074a063

Cited by 37 publications

(13 citation statements)

References 6 publications

(6 reference statements)

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“…Positive radical molecular ions were observed for all complexes except Zn(acac) 2 , although the relative abundance appears to decrease across the period, and there is little or no fragmentation. These results contrast with those for EI from our laboratory and from the literature, 14,20 where positive radical molecular ions and some fragmentation products were observed for all complexes, but this is to be expected due to the higher internal energies associated with EI. Positive radical ions were also observed for Fe(acac) 2 by CI, ESI, and LSIMS, and for Co(acac) 2 by LSIMS.…”

Section: Metal(acac) 2 Complexescontrasting

confidence: 99%

Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Wyatt

Havard

Stein

et al. 2007

Rapid Comm Mass Spectrometry

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Transition-metal acetylacetonate complexes of the form Metal(acac)(2), where Metal = Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), and Metal(acac)(3), where Metal = V(III), Cr(III), Mn(III), Fe(III), and Co(III), were investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The data was acquired using the aprotic, electron transfer matrix, 2-[(2E)-3-(4-tert-butylphenyl)-2-methylprop-2-enylidene]malononitrile (DCTB), and the observation of positive radical ions is shown clearly to depend on the metal element and the oxidation state it occupies. The ionization energy of DCTB was calculated to be 8.08 eV by density functional theory methods, which is notably lower than the experimental value, but within the range of other computational values. This value is very close to those of the analytes, so the existing electron transfer mechanism which is based on the ionization energies of the matrix and analyte, cannot be used predictively. Similarly, the data neither proves nor disproves the validity of the existing electron transfer ionization mechanism, with respect to metal coordination complexes without strong chromophores. In this case, periodic trends may be more useful in explaining the observed species and the prediction of species from sets of similar complexes. The addition of a sodium salt benefits the MALDI-TOFMS characterization of certain compounds studied, but the benefit of the addition of ammonium or silver salts is negligible.

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Section: Metal(acac) 2 Complexescontrasting

confidence: 99%

Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Wyatt

Havard

Stein

et al. 2007

Rapid Comm Mass Spectrometry

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“…For personal use only. (6) are similar to those observed in a previous study (7) on P-diketonates of Cr(III), and are consistent with variations to be expected for substituents bonded to a quasi-aromatic ring (compare ionization potentials of benzene, toluene, xylene, trimethylbenzene, and trifluoromethylbenzene given in Table 6). Under points (c) and (d) the effects of the phenyl, 2-furyl, and 2-thenyl substituents are smaller than expected when the ionization potentials of benzene, toluene, and biphenyl are compared.…”

Section: Appearance Potentialssupporting

confidence: 91%

Mass spectral studies of metal chelates. VI. Mass spectra and appearance potentials of β-diketonates of copper(II)

Reichert¹,

Westmore²

1970

Can. J. Chem.

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The mass spectra of several copper complexes of e-diketones are discussed. The extent of fragmentation of the molecular ions depends upon the nature of the substituents on the chelate ring, being larger for electron-withdrawing, and smaller for electron-releasing subst~tuents. In a number of fragmentations, migration of an aryl group to the copper atom occurs. Hydrogen atom migrations are also observed in some fragmentations. Attempts are made to correlate the appearance potentials of the molecular ions with acid dissociation constants of the (3-diketones, formation constants and polarographic reduction potentials of the complexes, and Hammett o constants of the substituents.

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“…Following sublimation via direct insertion and EI, the recorded fragmentation pattern is in very good agreement with what was previously reported where the preferred loss of methyl groups was readily observed. 5,12,14,15 The molecular ion at m/z 261 is the base peak, and fragment ions at m/z 246 and 231 correspond to consecutive losses of CH 3 from the molecular ion. The loss of one ligand from the molecular ion and the subsequent loss of CH 3 are also observed at m/z 162 and 147, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…3,4 The continued popularity of these compounds probably stems from their volatile nature, ease of preparation, thermal stability and tunability through ligand substitution. Mass spectrometric techniques have been commonly employed to investigate this class of compounds [5][6][7][8][9][10][11][12][13][14][15][16][17]21 with a focus on their propensity for polynuclear or cluster formation and the subsequent stability of such species. Mass spectrometry (MS) has also shed light on the ensuing fragmentation of various metal b-diketonate complexes using techniques where the loss of certain groups of a ligand or the loss of an entire ligand is commonly observed.…”

mentioning

confidence: 99%

Gas‐phase ligand exchange of select transition‐metal acetylacetonate and hexafluoroacetylacetonate complexes

Lerach

Leskiw

2008

Rapid Comm Mass Spectrometry

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Gas-phase ligand exchange reactions between M(acac)(2) and M(hfac)(2) species, where M is Cu(II) and/or Ni(II), were observed to occur in a double-focusing reverse-geometry magnetic sector mass spectrometer. The gas-phase mixed ligand product, [M(acac)(hfac)](+), was formed following the co-sublimation of either homo-metal or hetero-metal precursors. The gas-phase formation of [Cu(acac)(hfac)](+) from hetero-metal precursors is reported herein for the first time. The [Ni(acac)(hfac)](+) complex is also observed for the first time to form following the co-sublimation of not only Ni precursors, but also from separate Ni and Cu precursors. The corresponding fragmentation patterns of these species are also presented, and the mixed metal mixed ligand product [NiCu(acac)(2)(hfac)](+) is observed.

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Mass spectral studies of metal chelates. IV. Mass spectra, appearance potentials, and coordinate bond energies of bis(acetylacetonate)metal(II) complexes of the first transition series

Cited by 37 publications

References 6 publications

Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Mass spectral studies of metal chelates. VI. Mass spectra and appearance potentials of β-diketonates of copper(II)

Gas‐phase ligand exchange of select transition‐metal acetylacetonate and hexafluoroacetylacetonate complexes

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